-2х+8х=-12х
6x=-12x
6x+12x=0
18x=0
x=0
---------------------------------
5х-3х=15-17
2x=-2
x=-1
---------------------------------
3х-5х=-21+33
-2x=12
x=-6
---------------------------------
-7х-9х=-40+8
-16x=-32
x=2
---------------------------------
-3х+10х=-15-6
-7x=-21
x=-3
---------------------------------
7х-5х=17-35
2x=-18
x=-9
---------------------------------
5х-7х=-35+37
-2x=2
x=-1
---------------------------------
-2х-9х=-40+8
-11x=-32